Windows: Duplicate "Unable to load dynamic library" warning

Description

The following code:

$ php -v 
PHP Warning:  PHP Startup: Unable to load dynamic library 'ftp' (tried: ext\ftp (Das angegebene Modul wurde nicht gefunden), ext\php_ftp.dll (Falscher Parameter)) in Unknown on line 0

Warning: PHP Startup: Unable to load dynamic library 'ftp' (tried: ext\ftp (Das angegebene Modul wurde nicht gefunden), ext\php_ftp.dll (Falscher Parameter)) in Unknown on line 0
PHP 8.2.12 (cli) (built: Oct 24 2023 21:15:35) (NTS Visual C++ 2019 x64)
Copyright (c) The PHP Group
Zend Engine v4.2.12, Copyright (c) Zend Technologies

$ php -v 2>/dev/null

Warning: PHP Startup: Unable to load dynamic library 'ftp' (tried: ext\ftp (Das angegebene Modul wurde nicht gefunden), ext\php_ftp.dll (Falscher Parameter)) in Unknown on line 0
PHP 8.2.12 (cli) (built: Oct 24 2023 21:15:35) (NTS Visual C++ 2019 x64)
Copyright (c) The PHP Group
Zend Engine v4.2.12, Copyright (c) Zend Technologies

But I expected this output instead:

-> no warning in the output when stderr is redirected
-> one warning is propery redirected but it seems the very same warning is emitted a second time on stdout?

PHP Version

8.2.12

Operating System

windows11

Windows 11 で php -v と php -v 2>/dev/null を使って動作を再現し、重複した起動時警告とリダイレクトされた出力を比較します。例に関係する CLI の起動と警告出力の経路を追跡します。警告が一度だけ出力され、期待どおり stderr のリダイレクトに従えば完了です。